overgrowth

noun

over·​growth ˈō-vər-ˌgrōth 

1

a

: excessive growth or increase in numbers

an overgrowth of bacteria … may achieve pathogenic proportions

—Journal of the American Medical Association

an overgrowth of yeast in the mouth

b

: hypertrophy, hyperplasia

2

: something (as cells or tissue) grown over something else